CN108525168B

CN108525168B - Foam generating method and application thereof and fire extinguishing method

Info

Publication number: CN108525168B
Application number: CN201710646122.1A
Authority: CN
Inventors: 牟小冬; 郎需庆; 牟善军; 姜春明; 尚祖政; 吴京峰; 谈龙妹; 于辉; 王林; 陶彬; 刘全桢
Original assignee: China Petroleum and Chemical Corp; Sinopec Qingdao Safety Engineering Institute
Current assignee: China Petroleum and Chemical Corp; Sinopec Qingdao Safety Engineering Institute
Priority date: 2017-03-01
Filing date: 2017-08-01
Publication date: 2021-05-28
Anticipated expiration: 2037-08-01
Also published as: AU2018226928A1; US20230149753A1; EP3590580B1; US20210283442A1; AU2018226928B2; EP3590580A1; CN110913958A; US11559711B2; EP3590580A4; US11980785B2; CN110913958B; CN108525168A

Abstract

The invention discloses a foam generating method, application thereof in fire extinguishing and a fire extinguishing method, wherein the foam generating method comprises the steps of mixing gas with foaming substances so as to enable the foaming substances to generate foam, at least part of the gas is generated by a gas source instantly, and the ratio of the volume of the gas generated by the gas source to the volume of the gas source is not lower than 40. The foam generating method of the invention adopts the mode of mixing the gas basically generated in situ by the gas source with the foaming material for the first time, and the volume ratio of the gas generated by the gas source to the gas source is higher, so that the volume of a container for storing the gas source can be greatly reduced, and the small-volume storage equipment can replace a huge air compressor, an air compressor set or other high-pressure gas storage equipment. According to the invention, inert media such as liquid nitrogen participate in foam foaming, and inert gases are released after the foam is broken, and the inert gases can also play a role in inhibiting combustion on the surface of a combustion substance, so that the method is favorable for accelerating fire suppression.

Description

Foam generating method and application thereof and fire extinguishing method

Technical Field

The invention relates to a foam generating method, application thereof in fire extinguishing and a fire extinguishing method.

Background

The existing compressed gas foam fire extinguishing mainly adopts a mode of mixing high-pressure gas and foam mixed liquid to generate foam to extinguish fire. The specific foam fire extinguishing mode mainly comprises two modes of pressure stabilizing type compressed gas foam fire extinguishing and gas storage type foam fire extinguishing. The compressed gas foam fire extinguishing method generally adopts a gas compressor, a high-pressure gas pipe network or a compressed gas steel cylinder to supply gas, the gas compressor and the compressed gas steel cylinder have limited gas supply amount and cannot meet the requirements of large flow, high pressure and long-time gas supply, most places do not have the high-pressure gas pipe network, and if the large flow, high pressure and long-time gas supply is needed, a plurality of compressors or compressed gas steel cylinders are needed to be arranged (for example, a foam fire truck with the flow of 150L/S is taken as an example, the gas supply flow is at least 1050L/S, and the gas supply needs to be supplied by a plurality of large-scale air compressors), so that the occupied space is large, the space which is not arranged in the oil depot tank area and the device area is not favorable for field arrangement.

Another gas storage type foam fire extinguishing method is that compressed gas is stored in a fire extinguishing agent container generally, when the compressed gas is sprayed at a large flow rate, the compressed gas is consumed in a large amount, at the moment, in order to ensure the high-pressure spraying of the fire extinguishing agent, the compressed gas needs to be supplemented into the fire extinguishing agent container in time, and under the large-flow spraying state, sufficient supplement of the compressed gas cannot be ensured by only an air compressor and a compressed gas steel cylinder, so that the high-pressure spraying requirement cannot be effectively realized, along with the continuous spraying, the pressure in the container is obviously reduced, the foam performance gradually deteriorates, and the fire extinguishing effect is influenced. When major fire extinguishment is carried out, large-flow high-power foam is required to be produced for extinguishment, the flow of foam mixed liquid is increased at the moment, the gas supply amount of compressed gas is increased, the existing gas supply mode cannot realize the supply of large-flow high-pressure compressed gas, the maximum flow of the foam mixed liquid of the current compressed gas foam fire truck is only 15-20L/s, and the foam mixed liquid is mainly applied to fire suppression on a general scale at present, such as building fire, small-range ground flowing fire and the like, and cannot be applied to large-scale storage tank fire or large-scale ground flowing fire.

Disclosure of Invention

The object of the present invention is to overcome the drawbacks of the prior art high pressure gas supply technology and to provide a new method for generating foam, which enables a larger amount of foam to be obtained with a smaller apparatus and which has a higher extinguishing efficiency when used for extinguishing fires.

In order to achieve the above object, the present invention provides, in one aspect, a foam generating method comprising mixing a gas with a foamable material so that the foamable material generates foam, at least part of the gas being instantly generated by a gas source having a gas production rate of not less than 40.

In a second aspect the invention provides the use of the above method for extinguishing fires in a variety of locations.

The third aspect of the present invention also provides a fire extinguishing method, which generates foam using the above foam generating method and then outputs the foam to extinguish a fire.

The foam generating method provided by the invention adopts a mode of mixing the gas generated by the gas source in situ or basically in situ with the foaming substance for the first time, and the volume ratio of the gas generated by the gas source to the gas source is higher, so that the volume of a container for storing the gas source can be greatly reduced, and a small-volume storage device can replace a huge air compressor or air compressor set.

When the method for generating the foam is used for fire extinguishing, the fire fighting equipment has high response speed, can quickly respond in a short time to generate a large amount of gas, can replace the traditional gas supply modes such as an air compressor, a compressed gas steel cylinder, a high-pressure gas pipe network and the like, can meet the requirement of generating large-flow high-pressure gas supply required by large-flow high-multiple foam, provides enough gas flow for large-flow injection of a compressed gas foam fire extinguishing system and a gas storage type foam fire extinguishing system, and realizes effective application in major fire extinguishing; and because the gas supply time is long, external power is not needed, the independent working capacity is strong, the condition that a plurality of air compressors are required to be arranged and the occupied space of a compressed gas steel cylinder is large when the large-flow injection is required is avoided, the occupied space is small, the arrangement is flexible, and the field arrangement and the fire extinguishing work are convenient to develop.

Drawings

FIG. 1 is a schematic diagram of a foam generation system according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a gas-liquid mixing device of the foam generating system according to the embodiment of the present invention;

FIG. 3 is a schematic structural view of a spoiler having a tapered configuration;

FIG. 4 is a schematic structural view of a spoiler having a hemispherical structure;

fig. 5 is a schematic view of a spoiler structure of the platform structure.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the volume of the gas device required when a large flow of foam is required is reduced by using a specific kind of gas source instead of conventional compressed air. The gas source is required to (1) rapidly and instantly generate gas and the generated gas can be conveniently mixed with the foaming material to generate bubbles; (2) the volume of gas generated by the gas source is greatly increased compared with the volume of the gas source itself, the ratio of the volume of gas that the gas source can generate to the volume of the gas source itself is not less than 40, and the compression ratio of conventional compressed air is not more than 20, whereby the volume of the gas source can be greatly reduced with the same amount of gas available.

In the present invention, the term "gas" means a gas that is generated before being mixed with a foaming material, and the gas is preferably mixed with the foaming material within 60 minutes, preferably within 60 seconds, more preferably within 20 seconds, and even more preferably within 10 seconds after being generated from a gas source, as compared with the conventional method in which a gas is generated first, stored in a gas tank with or without compression, and then released and mixed with the foaming material. That is, in the present invention, the instant generation means that the time from generation of the gas to mixing with the foaming substance does not exceed 60 minutes, for example, 59 minutes, 55 minutes, 50 minutes, 45 minutes, 40 minutes, 35 minutes, 30 minutes, 25 minutes, 20 minutes, 15 minutes, 10 minutes, 9 minutes, 8 minutes, 6 minutes, 5 minutes, 4 minutes, 3 minutes, 2 minutes, 60 seconds, 55 seconds, 50 seconds, 45 seconds, 40 seconds, 35 seconds, 30 seconds, 25 seconds, 20 seconds, 15 seconds, 10 seconds, 9 seconds, 8 seconds, 7 seconds, 6 seconds, 5 seconds, 4 seconds, 3 seconds, 2 seconds, 1 second, 0 second. The rapid mixing of the gas generated by the gas source with the foamable material may be achieved by controlling the distance between the gas source and the mixing device and/or the pressure at which the gas source generates the gas.

Some or all of the gas may be generated instantaneously in the manner described above, preferably at least 20% by volume, preferably at least 60% by volume, more preferably 100% by volume, of the gas is generated instantaneously by the gas source in order to take advantage of the reduced volume of the gas storage device. That is, in the present invention, at least partially means at least 20% by volume, for example, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% by volume.

In the present invention, the kind of the gas source is such that the gas production rate is not less than 40, preferably not less than 100, more preferably 200-. By having the gas production rate within the above range, the volume of the gas source can be greatly reduced, thereby reducing the volume of the foam generating system. The compression ratio of the compressed air used in the compressed gas foam system is generally less than 20.

In the present invention, the volume of gas that can be generated by the gas source refers to the maximum volume of gas that can be generated by the gas source, and the volume refers to the volume at room temperature and differential pressure.

In the present invention, the volume of gas that the gas source is capable of producing can be obtained in various ways. For example, when the gas source is a liquefied medium, the ratio is the expansion ratio of the liquefied medium. When the gas source is a chemical gas production agent, the ratio can be calculated according to the standard volume of gas which can be obtained by the chemical gas production agent per unit weight. Wherein the standard volume of gas available per unit weight of chemical gas generant composition is obtained in accordance with ISO standard 12097-3(2002) part 3 of road vehicle airbag module-gas generator set test.

In the present invention, the gas source may be any of a variety of substances that can conveniently generate a gas or gases under mixing conditions to mix with the foaming substance to produce a foam.

It is clear that when the foam produced is used in a subsequent particular application, the gas produced by the gas source must not adversely affect the subsequent application. For example, when the foam produced is to be used to extinguish a fire, the gas produced by the gas source should be conducive to extinguishing the fire without having a destructive effect on the foam itself, such as by dissolving in the foam concentrate, by reacting chemically with one or more components of the foam, by generating gas at too high a temperature to promote collapse of the foam, and the like.

In the present invention, the manner of instantly generating the gas may be various manners capable of satisfying the above requirements, for example, the gas may be generated in situ by a physical and/or chemical reaction during the mixing process, or may be instantly generated by a gas source under an external force by a physical and/or chemical reaction before mixing.

According to a preferred embodiment of the present invention, the gas source is a liquefied medium, preferably the liquefied medium is at least one of liquid nitrogen, liquid carbon dioxide, liquefied inert gas, liquefied halogenated hydrocarbon gas.

When the gas source is a liquefied medium, since the liquefied medium is gasified to a gas under a normal room temperature environment, the gas can be obtained without additional operation. Thus, when the gas source is a liquefied medium, the mixing comprises passing the gas source into the foamable material in a liquid stream for mixing. Since the foaming substance is generally at ambient temperature and the mixing is usually carried out at ambient temperature, the liquefied medium is gasified during entry into the mixer and during contact with the foaming substance, producing a large amount of gas, which is foamed.

Aiming at the problem of supplying large-flow compressed gas, the invention avoids the technical route of supplying gas by a large-scale air compressor or a machine set thereof, and also avoids the route that liquefied media such as liquid nitrogen and the like are subjected to heat exchange and gasification through a large-scale gasification device to produce a large amount of compressed gas and then the compressed gas is mixed with foaming substances, but adopts the mode that the gas source instantly generates gas and then is mixed with the foaming substances to foam.

The liquefied inert gas may be any of various liquefied inert gases. The inert gas refers to a gas of an element in the zero group of the periodic table.

In the invention, the liquefied medium such as liquid nitrogen is used as a gas source to replace conventional compressed air, so that the volume of a gas device required when large-flow foam is required can be reduced, and the large-flow foam fire extinguishing can be used in various occasions.

Since the liquefied medium such as liquid nitrogen can rapidly generate gas and the generated gas can be conveniently mixed with the foaming substance to generate bubbles, and the expansion ratio of the liquefied medium is usually larger than 40, and some is even more than 500, for example, the expansion ratio of liquid nitrogen is usually 710, that is, 1 volume of liquid nitrogen can usually provide 710 volumes of nitrogen, and the compression ratio of conventional compressed air is not more than 20, so that the volume of the gas generated by the liquefied medium is greatly increased compared with the volume of the liquefied medium per se, the volume of a gas source can be greatly reduced under the condition of obtaining the same amount of gas, therefore, the liquefied medium such as liquid nitrogen can be directly used as the gas source to be mixed with the foaming substance to generate foam without gasifying the liquefied medium outside the foaming device firstly, and then sending the gasified gas into the foaming device to be mixed with the foaming substance, thereby greatly reducing the volume of the device, the flexibility of the device is improved and the application places are widened.

The arrangement of negative pressure type foam (air suction type foam), compressed gas foam supplied with gas from liquid nitrogen, and compressed gas foam supplied with gas from a compressor unit were compared and analyzed by taking the case of extinguishing a full-area fire of a 10-ten-thousand-cubic meter storage tank as an example.

(1) For the negative pressure type foam fire extinguishing system, based on the abroad fire extinguishing cases, the international authoritative standard specifications such as Japanese fire-fighting Law, API, LASTFIRE and the like and the recommended value of the storage tank fire research organization, for the fire fighting of the whole area of the 10-ten-thousand cubic meter storage tank, the supply intensity of the foam mixed liquid is up toLess need of 9L/min.m²The flow rate of the foam mixed liquid needs to be at least 45216L/min, the fire extinguishing time needs to be at least 60min, and the consumption of the foam mixed liquid is 2712m³。

(2) For the compressed gas foam fire extinguishing system supplied with air by the compressor, the foam supply intensity required by the compressed gas foam fire extinguishing system is generally considered to be 1/4 of the negative pressure type foam fire extinguishing system, but due to the fact that the fire extinguishing area of a 10-ten-thousand cubic meter storage tank full-area fire is large, according to the fire extinguishing experimental data of the large-scale oil pan of the inventor of the invention, the foam supply intensity is more suitably 5.4L/min²The flow rate of the foam mixture was 27130L/min. The gas supply amount is not less than 200m with the foaming multiple of 7 as the target³And/min. According to the air supply capacity (20-28 m) of the current large-scale air compressor unit³Min), 7-10 large air compressors are required to be arranged in parallel for air supply, and the floor area of each air compressor is about 5-6m²The total floor area of the air compressor set is 35-70m². The extinguishing time is 60min, and the consumption of foam mixed liquor is 1627m³. The fire extinguishing test of the large-scale oil pan refers to that diesel oil is ignited in an oil pool with the diameter of 21m to form a full-area fire, and then foam is sprayed into the oil pan by using a foam fire extinguishing device to perform a fire extinguishing test.

(3) For the compressed gas foam fire extinguishing system supplied with gas by liquid nitrogen, the foam supply intensity is also 5.4L/min²The flow rate of the foam mixture was 27130L/min. The gas supply amount is not less than 200m with the foaming multiple of 7 as the target³And/min. The air supply amount in 60min is 12000m³The volume of the gasified liquid nitrogen is 710 times, so the required liquid nitrogen amount is 17m³. The actual fire extinguishing time is 60min, and the consumption of foam mixed liquid is 1627m³. The volume of a liquid nitrogen tank truck is generally 25m³The floor area is about 10 square meters. After the liquid nitrogen tanker was fully loaded with liquid nitrogen, the continuous feed time was 88 min. Specific examples are given in table 1 below.

TABLE 1

It can be seen from the comparison that the liquid nitrogen gas supply mode of the invention can greatly reduce the field area required by the gas supply equipment, reduce the gas supply difficulty and enable large-area fire extinguishing.

Since a liquefaction medium such as liquid nitrogen is gasified into a gas under a normal room temperature environment, the gas can be obtained without additional operation.

When liquid nitrogen is used as a gas source and the foam mixed liquid is used as a foaming substance, the foam mixed liquid is a main normal-temperature fluid, and after the foam mixed liquid and the liquid nitrogen are mixed according to the proportion, the foam mixed liquid can fully exchange heat with the liquid nitrogen, and the liquid nitrogen is quickly gasified in the foam mixed liquid and immediately participates in foaming. After the liquid nitrogen is gasified, the foam mixed liquid has little reduction of the liquid temperature due to large flow, and the foam mixed liquid can be ignored completely without influencing the foam quality. Even if the liquid nitrogen is contacted with the foam mixed liquid for the first time, a small amount of ice slag can be generated by the foam mixed liquid, but the ice slag can be melted quickly in the subsequent flow, and the foaming and foam spraying are not influenced at all.

Although the liquid nitrogen is also partially gasified during transportation before being mixed with the foaming substance to generate gas, the amount of the gas is relatively small, most of the gas is generated during contact with the foaming substance and is immediately mixed with the foaming substance to foam, and the gas can participate in foaming, so that the invention still remains in the scope of "instant" gas generation.

The ratio of gas source to foamable material can be calculated from the amount of gas required for the foamable material and the amount of gas that the gas source is capable of producing. For a liquefied medium, the gas production rate is the expansion ratio of the liquefied medium. The volume ratio of the gas source to the foaming substance is 1: 40-300, preferably 1: 60-200. In the case of liquid nitrogen, one part of liquid nitrogen is gasified to 710 parts of nitrogen, i.e. the volume is expanded by 710 times. According to experimental test results, the volume flow ratio of the foam mixed liquid to the liquid nitrogen is in the range of 60-200:1, and good compressed gas foam can be realized.

The inventors of the present invention have found that, when the foaming material is a foam mixture, a compressed gas foam having a better quality can be obtained when the flow rates of the liquefaction medium and the foaming material satisfy the following relationship: l is mV/nf. Wherein L is the volume flow of the liquefied medium, m is the set foaming multiple, the value is generally in the range of 5-200, preferably 5-20, more preferably 6-8, V is the volume flow of the foaming substance, n is the ratio of the gas volume which can be generated by the gas source to the volume of the gas source, and f is the pipeline loss, and the value is in the range of 1-1.4. Wherein the volume flow V of the foaming substance is determined by the foam fire extinguishing system design Specification (GB50151-2010) according to the fire area. Better quality of compressed gas foam means that the foam lasts longer and is less prone to rupture, resulting in better fire fighting.

Preferably, the liquefaction medium is mixed with the foam mixture at a pressure of 1MPa or more, preferably 1-2 MPa; the foam mixture is mixed with the liquefaction medium at a pressure of 0.8MPa or more, preferably 0.8-1.5 MPa.

In the present invention, a chemical gas generating substance (e.g., a substance called "chemical gas generating agent" in the field of airbags) may be used as a gas source to generate a gas for foaming by chemically reacting the chemical gas generating substance by an external force. The chemical gas-generating substance is generally solid, and occupies smaller volume, so that the volume of the foaming device and the whole application device can be greatly reduced.

Preferably, the chemical gas-producing substance is at least one of sodium azide, ammonium nitrate, nitrocellulose, a hexogen gas-producing drug and a nitroguanidine gas-producing drug.

The gas is generated by chemically reacting a chemical gas generating substance, preferably a chemical gas generating agent, more preferably at least one of sodium azide, ammonium nitrate, nitrocellulose, a hexogen gas generating agent, and a nitroguanidine gas generating agent, in various manners known in the art, preferably in various manners that can be achieved without requiring any special process or complicated apparatus, including but not limited to at least one of an impact force, heating, a pressure difference, a chemical reaction, and ignition.

The mode skillfully refers to the mode of generating gas by the automobile safety airbag, so the specific operation and conditions can refer to the technology. Since the gas source is generally solid, the volume of the gas source can be greatly reduced. Specific examples thereof include CN 1903805A, CN 101077846A, CN 101205159 a.

The nitrocellulose is also called nitrocellulose, i.e. a product obtained by esterification reaction of cellulose hydroxyl and nitric acid. The nitrogen content of the nitrocellulose in the gas generant composition of the present invention is preferably 10 to 14.1% by weight. Nitrocellulose is commercially available or can be prepared by known methods from esterification of cellulose (e.g. cotton fibre or wood pulp) with nitric acid under the catalysis of concentrated sulphuric acid.

In order to increase the gas production rate of nitrocellulose, it is preferable to obtain a gas producing pharmaceutical composition by blending it with a stabilizer. The content of the stabilizer may be 0.1 to 20 parts by weight, preferably 0.2 to 15 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of nitrocellulose.

The stabilizer is preferably an amine and/or urea. The amine can be various amines which can prolong the storage time of the gas producing medicine, and the preferable examples of the amine include but are not limited to one or more of aniline, ketone amine, aldehyde amine and quinoline; the urea may be any of the various ureas available to prolong the shelf life of gas generant compositions, with preferred examples of ureas including, but not limited to, diethyldiphenylurea, and dimethyldiphenylurea. The aniline may be diphenylamine, the ketoamine may be acetone diamine, the aldehyde amine may be diphenylaldehyde amine, and the quinoline may be phenyl-alpha-naphthylamine.

The gas generant composition may further contain nitroguanidine. The content of nitroguanidine may be 0 to 80 parts by weight, preferably 2 to 80 parts by weight, more preferably 5 to 60 parts by weight, based on 100 parts by weight of nitrocellulose. Nitroguanidine is added into the gas production medicine, so that the thermal stability of the gas production medicine can be improved, and the temperature of the gas generated by the gas production medicine containing nitroguanidine and nitrocellulose is lower than that of the gas generated by the gas production medicine without nitroguanidine, so that the danger of burning an air bag or scalding passengers can be completely avoided after the gas is filtered by a filter.

The gas generant composition of the invention may also contain one or more of a co-solvent, a plasticizer and a combustion catalyst as desired.

The cosolvent may be a substance which helps to dissolve the nitrocellulose and the stabilizing agent in the solvent during the preparation process of the gas generant composition, and is preferably one or more of dinitrotoluene, camphor and nitrobenzene. The content of the co-solvent may be 0 to 20 parts by weight, preferably 0.1 to 15 parts by weight, more preferably 0.3 to 10 parts by weight, based on 100 parts by weight of nitrocellulose.

In order to increase the gas yield of sodium azide, it is preferable to use an auxiliary, an alkali metal nitrate, a metal sulfide and/or a metal oxide. Based on the total weight of the chemical gas production medicament, the content of the sodium azide is 45-60 wt%, the content of the metal sulfide and/or the metal oxide is 35-50 wt%, the content of the alkali metal nitrate is 1.5-5 wt%, and the content of the auxiliary agent is 0.5-6 wt%.

The auxiliary agent preferably adopts one or more of molybdenum disulfide, aluminum oxide and magnesium trisilicate; more preferably magnesium trisilicate or magnesium trisilicate in combination with one of the other two; more preferably, three are simultaneously adopted; the weight ratio of the molybdenum disulfide to the aluminum oxide to the magnesium trisilicate is 1:0.1-3: 0.1-3. Because the molybdenum disulfide, the aluminum oxide and the magnesium trisilicate are not corrosive and are smooth and loose, the gas production medicine prepared by mixing has good fluidity and is easy to form; and the aluminum oxide can also play a role in slagging, so that the gas production medicine is easy to form loose large residues after combustion, and the magnesium trisilicate can also enable the residues to become loose so as to absorb sparks more easily, so that the residues are not easy to spray.

The metal sulfide is selected from one or more of group IB, group IIB and group VIIIB metal sulfides in the periodic table of elements, such as one or more of ferrous sulfide, zinc sulfide and copper sulfide, and ferrous sulfide is preferably adopted.

The metal oxide is selected from one or more of group IB, group IIB and group VIIIB metal oxides in the periodic table of elements, such as one or more of copper oxide, zinc oxide and ferric oxide; preference is given to using iron trioxide and/or zinc oxide.

Since the metal sulfide reacts with sodium azide more easily than the metal oxide, the chemical reaction of the gas generant composition proceeds more easily and sufficiently, and therefore, the metal sulfide is preferably used.

The nitrate of the alkali metal is taken as an oxidant and releases oxygen in the reaction, and the nitrate of the alkali metal is selected from one or more of potassium nitrate, sodium nitrate and lithium nitrate, preferably potassium nitrate and/or sodium nitrate.

When the gas source is a chemical gas-producing substance, the amount of the chemical gas-producing substance is determined by the gas production amount of the chemical gas-producing substance and the foaming multiple, preferably, the amount of the chemical gas-producing substance is calculated according to the following formula:

M＝ρf(m+2)V/1000n

wherein M is the mass (kg/min) of the chemical gas-producing substance required per unit time, and ρ is the density (kg/M) of the chemical gas-producing substance³) F is a correction coefficient (generally 1-1.4), m is a set foaming multiple, the value is generally within the range of 5-200, preferably 5-20, more preferably 6-8, V is the volume flow rate (unit is L/min) of the foam mixed liquid, and n is the ratio of the volume of the gas which can be generated by the chemical gas generating substance to the volume of the chemical gas generating substance (generally n is between 100 and 800). Wherein n can be obtained by converting the standard volume amount of the gas which can be obtained by the chemical gas production medicine with unit weight and the density of the chemical gas production substance. The standard volume of gas available per unit weight of chemical gas generant composition is obtained in accordance with standard ISO 12097-3(2002) part 3 of road vehicle airbag module-gas generator assembly test. Wherein the volume flow V of the foaming substance is determined by the foam fire extinguishing system design Specification (GB50151-2010) according to the fire area.

The chemical gas production substance and the foam mixed liquid are provided by adopting the formula, and compressed gas foam with better quality can be obtained.

According to this embodiment, the chemical gas generating substance can be stably present without chemical reaction when foam generation is not required. When the foam is required to be generated, the chemical gas generating substance is subjected to chemical reaction so as to generate gas. In other words, the gas to be mixed with the foaming substance is not previously generated and stored in the container by the chemical gas-generating substance, because it results in the need to provide a plurality of containers for storing the gas, which in turn results in inconvenience in use and in on-site arrangement.

The chemical gas-generating substances can be stored in one or more containers, and chemical reactions are simultaneously or sequentially started to generate gas according to the required amount of the gas during foaming.

Thus, instantaneously generating gas means: when foam is needed to be generated, the chemical gas generating substance is subjected to chemical reaction so as to generate gas. This makes it possible to dispense with a plurality of containers for storing the gas, thereby facilitating the implementation of the foam production method of the invention and facilitating the on-site deployment.

According to the present invention, in order to reduce the volume of the foaming device, it is obvious that the above-mentioned method can be used to achieve the object, as distinguished from the conventional method of generating gas from the outside in advance and mixing the gas with the foaming substance. For example, a part of the gas may be supplied in the conventional manner, and the other part of the gas may be supplied in the instant generation manner as described in the present invention, so that the present invention may be such that a part of the gas is generated in advance outside the foaming device and then the gas is mixed with the foaming substance, or all of the gas may be generated in the instant generation manner and then mixed with the foaming substance within 60 minutes, preferably within 60 seconds, more preferably within 20 seconds, even more preferably within 10 seconds. The quick mixing of the gas generated by the chemical gas generating substance and the foaming substance can be realized by controlling the distance between the chemical gas generating substance and the mixing device and/or the pressure of the gas generated by the chemical gas generating substance. The gas produced outside the foaming device in advance can be supplied by an existing air compressor, or can be liquefied by the liquefaction medium of the invention and/or can be produced by chemical reaction of chemical gas production substances. That is, the present invention also includes the following embodiments: the gas obtained by liquefying the liquefying medium and/or generated by chemical reaction of the chemical gas-generating substance is firstly sent into a storage tank for storage for more than 60 minutes or less, and then is mixed with the foaming substance for foaming.

The invention mainly achieves the aim by changing the source of the gas for foaming, namely, generating the gas in situ (instantly) through chemical reaction of a chemical gas generating substance to replace the prior air compressor to provide the gas, so the type and the amount of the gas, the type of the foaming substance, the mixing condition and the mixing mode are not particularly limited, and the invention can be realized by referring to the prior art teaching.

In the present invention, the foaming substance may be any of various substances which can generate foam by increasing the volume thereof upon contact with a gas. According to a preferred embodiment of the invention, the foaming substance is a foam mixture, the mixing comprising contacting the gas source and the foaming substance each in the form of a liquid stream. The foam mixed liquid is a foaming source for generating foam in the fire fighting field, and comprises a mixture of a protein foam liquid, a fluorine protein foam liquid, an aqueous film-forming foam liquid, a water-based foam liquid, an anti-dissolved fluorine protein foam liquid, an anti-dissolved aqueous film-forming foam liquid and the like with water, and generally contains various additives such as surfactants, stabilizers and the like.

According to another embodiment of the invention, the foamable material is a foam concentrate and the mixing comprises contacting the gas source, foamable material and water each in a liquid stream. Preferably, the volume ratio of the gas source to the foaming substance to the water is 1: 1-10: 50-300, preferably 1: 3-7: 80-160.

Wherein the foam stock solution is protein foam solution, fluorine protein foam solution, aqueous film-forming foam solution, water-based foam solution, anti-dissolved fluorine protein foam solution, anti-dissolved water film-forming foam solution, etc., and generally contains various additives such as surfactants, stabilizers, etc. And mixing the foam stock solution with a proper amount of water to obtain the foam mixed solution.

Both the foam stock solution and the foam mixed solution are commercially available.

The mixing conditions are not particularly limited, and may be at ordinary ambient temperature. Preferably, the mixing conditions include a mixing temperature of-30 ℃ to 60 ℃, preferably-10 ℃ to 40 ℃, more preferably 0-40 ℃. That is, the liquid nitrogen and the foaming substance may be mixed under the condition of-30 ℃ to 60 ℃, preferably-10 ℃ to 40 ℃, more preferably 0-40 ℃. Since the liquid nitrogen is gasified and then mixed with the foaming substance to form the foam, the mixing time is not particularly limited.

In the present invention, the mixing may be performed in various apparatuses capable of achieving the functions of mixing and foaming the foaming substance. The mixing device according to an embodiment of the present invention is described below by taking liquid nitrogen as a gas source as an example, and other liquefaction mediums are similar to the liquid nitrogen, which is not described in detail herein. Preferably, the mixing device may be a gas-liquid mixing device 1 as shown in fig. 2, the mixing device having a mixing chamber with a foaming substance inlet 11 for inputting a foaming substance, an inlet 12 for inputting a liquefied medium, and a foam outlet 13 for outputting foam; wherein in the mixing chamber the liquefied medium is mixed with a foaming substance and gasified to output foam for extinguishing fire from the foam outlet 13.

Flow meters, pressure gauges and control valves may be provided at each port to control the flow ratio of the foaming substance inlet 11 and the inlet 12.

As shown in fig. 2, the gas-liquid mixing device 1 is a cylindrical structure, one end of the cylindrical structure is provided with at least one foaming substance inlet 11, the other end of the cylindrical structure is provided with at least one foam outlet 13, and the inlet 12 and the foaming substance inlet 11 are arranged at an angle, so that two liquids can be input into the mixing cavity and simultaneously have certain cross flow, and the two liquids can generate turbulence to achieve good mixing effect.

Preferably, the foaming substance inlet 11 is provided with one, the inlet 12 is provided with one or more around the foaming substance inlet 11, and the angle between the direction of each inlet 12 and the direction of said foaming substance inlet 11 is 0-90 °, more preferably 30-60 °. In the embodiment shown in fig. 2, one inlet 12 is provided; in further embodiments, the inlet 12 may be provided in plurality around the foaming substance inlet 11.

In the case where the foaming substance inlet 11, the inlet 12 and the foam outlet 13 are each provided one by one, the relationship between the diameter D1 of the cylindrical structure and the diameter D2 of the foaming substance inlet 11 is: D1/D2 is 1.1-4, preferably D1/D2 is 1.4-2.0; the relation between the diameter D2 of the foaming substance inlet (11) and the diameter D3 of the liquid nitrogen inlet (12) is: D2/D3 is 4-10; the relationship between the diameter D1 of the cylindrical structure and the diameter D4 of the foam outlet (13) is: D1/D4 is 0.8-2, preferably D1/D4 is 0.8-1.2. By controlling the diameter of each opening to conform to the relationship, the aforementioned flow relationship can be achieved without additional control devices, thereby enabling more adequate foaming and resulting higher foam quality.

It will be understood by those skilled in the art that the foaming substance inlet 11, inlet 12 and foam outlet 13 are not limited to the arrangements described above, and various changes or modifications may be made to the arrangements of the foaming substance inlet 11, inlet 12 and foam outlet 13 for better mixing.

For example, in another embodiment, one foaming substance inlet 11 may be provided, the inlet 12 may be provided in plurality around the foaming substance inlet 11, and the plurality of inlets 12 are sequentially deviated in the direction from the radial direction in the lateral direction, so that the liquid stream entering from the inlet 12 can be rotated. Wherein, the direction of the cylindrical structure of the gas-liquid mixing device 1 from one end to the other end is the longitudinal direction, and the direction perpendicular to the longitudinal direction is the transverse direction.

In addition, a plurality of foam outlets 13 may be provided to connect to the injection lines, respectively, so that the foam is injected in a plurality of directions through one gas-liquid mixing device 1.

To better control the flow of liquid nitrogen entering from inlet 12, inlet 12 may be provided with an inlet pipe 16 (shown in FIG. 2) that extends into the mixing chamber.

In the present embodiment, at least one turbulence generator 14 for disturbing a liquid flow is provided in the mixing chamber of the gas-liquid mixing device 1.

Wherein the spoiler 14 may be formed as a cone-shaped structure (see fig. 3), a hemispherical structure (see fig. 4), a platform structure (see fig. 5), or other irregularly shaped structure. The conical top of the conical structure, the spherical top of the hemispherical structure or the plateau top surface of the plateau structure faces the foaming substance inlet 11.

Preferably, the cross section of the turbulence generator 14 is a circular structure, and the relationship between the diameter D7 of the turbulence generator 14 and the diameter D2 of the foaming substance inlet 11 is: D7/D2 is 1-4, preferably D7/D2 is 1.0-1.6. The distance L between the tip of the turbulence generator 14 and the outflow opening of the liquid nitrogen at the inlet 12 is 0-100 mm. In the preferred mode, the mixture can form turbulent flow, so that gas and liquid are mixed more fully, and foam with higher quality is obtained.

The spoiler 14 may be provided with a mounting portion 141 for fixing in the mixing chamber. As shown in fig. 2, the conical turbulence generator 14, the turbulence generator 14 is installed with the conical top facing the foaming material inlet 11, the liquid flow of the foaming material mixed with liquid nitrogen is rushed to the turbulence generator 14, the liquid flow can be broken up, the liquid flow is disturbed, and thus the liquid nitrogen and the foaming material are fully mixed, so as to obtain foam with even foaming and good performance.

Of course, the arrangement of the turbulence generator 14 is not limited to the above, for example, a plurality of turbulence generators may be arranged and distributed at different positions in the mixing chamber, and any type of turbulence generator capable of disturbing the flow of liquid may be used.

In the present embodiment, at least one porous structure 15 such as a perforated plate or a wire mesh, which is arranged at intervals, is further disposed in the mixing cavity of the gas-liquid mixing device 1, and each porous structure 15 is provided with a plurality of holes; the pores of the porous structure 15 are directed towards the foaming substance inlet 11 and the top of the porous structure 15 opposite the turbulence generator 14 is remote from the foaming substance inlet 11. The liquid flow broken up by the turbulence generator 14 is directed from the periphery of the turbulence generator 14 to the porous structure 15, and the liquid flow is further disturbed by the porous structure 15 to be further mixed.

In a specific application, the foaming substance inlet 11 can be connected with a container for containing the foaming substance, or connected with a stock solution mixer 2 for mixing the foaming stock solution and water to obtain the foaming substance; inlet 12 may be connected to a liquid nitrogen tank, for example, or a liquid nitrogen tanker.

The gas-liquid mixing device is also suitable for the mode when the gas source is a chemical gas production substance, and only when the gas source is the chemical gas production substance, the gas is generated by the chemical reaction of the chemical gas production substance in the gas production device through the gas production device, and the gas is input into the mixing device 1 to be mixed with the foaming substance to generate foam, so compared with the mixing device when the liquid nitrogen is the gas source, when the gas source is the chemical gas production substance, the gas enters the foam mixed liquid to foam, the gas amount is large, the gas inlet pipe diameter of the mixing device is large, the number of the gas inlet pipes is relatively more (generally 3-10), and when the liquid nitrogen is injected to foam, the liquid phase enters the foam, the liquid phase volume flow is low, the gas injection pipe diameter is small, and the liquid nitrogen is gasified and foams after. The relationship between the diameter D2 of the foaming substance inlet 11 and the diameter D3 of the gas inlet 12 is: D2/D3 is 2-6.

The foam generating method according to the present invention can be implemented by a foam generating system 100 shown in fig. 1, wherein the foam generating system 100 includes a gas generating device 3 for supplying instantly generated gas to a gas-liquid mixing device 1, a foaming substance supply device 4 for supplying a foaming substance, and the gas-liquid mixing device 1.

The gas production device 3 is an instant chemical gas production device, preferably a sodium azide decomposition reaction gas production device or an ammonium nitrate decomposition reaction gas production device, and is used for providing an instant gas production to the gas-liquid mixing device 1. The instant chemical reaction gas production device also comprises a gas treatment device. The gas treatment device can be used for filtering and purifying gas, and the stability of gas-liquid mixing proportion and the stability of output foam are improved. Sodium azide (NaN)₃) The decomposition reaction gas-making device can quickly produce decomposition reaction to produce large amount of nitrogen (N)₂) The requirement of large-flow gas supply of the foam generating device for large-flow high-multiple chemical reaction gas supply is met. Ammonium Nitrate (NH)₄NO₃) The decomposition reaction gas-making device can quickly produce decomposition reaction to produce large quantity of nitrous oxide (N)₂O) meets the requirement of large-flow gas supply of a foam generating device for large-flow high-multiple chemical reaction gas supply.

The gas generating device 3 has a gas outlet, and the foaming substance supply device 4 has a foaming substance outlet. The gas-liquid mixing device 1 has a mixing chamber for mixing gas and a foaming substance, and an inlet 12, a foaming substance inlet 11, and a foam outlet 13 are provided on a wall surface of the mixing chamber. Wherein, the inlet 12 is communicated with the gas outlet so that the gas provided by the gas generating device 3 enters the mixing cavity from the inlet 12, and the foaming substance inlet 11 is communicated with the foaming substance outlet so that the foaming substance provided by the foaming substance supply device 4 enters the mixing cavity from the foaming substance inlet 11.

The gas generating device 3 of the foam generating system 100 according to the embodiment of the present invention is used for placing a chemical gas generating substance, which can generate gas under the action of external force, wherein the ratio of the volume of the gas generated by the chemical gas generating substance to the volume of the gas generating agent is not lower than 40. The external force action may be achieved in a variety of ways that do not require special procedures or complicated apparatus, including but not limited to at least one of a collision force action, heating, a pressure differential, a chemical reaction, and ignition.

Preferably, the ratio of the foam mixed liquid and the gas in the gas-liquid mixing device is 1: 5-8.

The ratio of the volume of the gas generated by the chemical gas generating substance to the volume of the chemical gas generating substance is higher, so that the volume of a container for storing the gas generating medicine can be greatly reduced, namely, the volume of the gas generating device 3 can be greatly reduced, and the gas generating device 3 with small volume can replace a huge air compressor or air compressor set.

The invention adopts the instant chemical reaction gas-making device for producing inert gas to replace a large-scale movable air compressor and a steel cylinder in the prior art to supply gas for the gas-liquid mixing device, which is beneficial to the arrangement of fire-extinguishing sites. The foam generating system 100 avoids the technical route of gas supply of a large-scale air compressor unit and the route of producing a large amount of compressed gas by heat exchange and gasification of liquefied media such as liquid nitrogen through a large-scale gasification device, and realizes gas generation by the chemical gas generating substance by the gas generating device 3 and mixing of the gas and the foaming substance provided by the foaming substance supply device 4 by the gas-liquid mixing device 1 so as to continuously generate a large amount of foam capable of meeting the fire extinguishing requirement.

According to the foam generation system 100 of the embodiment of the invention, a large amount of foam capable of meeting the fire extinguishing requirement can be continuously generated without arranging a plurality of air compressors and a plurality of compressed gas steel cylinders. Therefore, the foam generating system 100 according to the embodiment of the present invention has the advantages of simple structure, low manufacturing cost, small occupied space, convenient field arrangement, etc., and can be applied not only to the fire suppression of general scale, such as building fire, small-scale ground flowing fire, etc., but also to the fire suppression of large-scale storage tank fire or large-scale ground flowing fire.

As shown in fig. 1-5, in some embodiments of the present invention, the foam generating system 100 may include a gas generating device 3, a foaming substance supply device 4, and a gas-liquid mixing device 1.

The gas production device 3 can be internally provided with a gas production medicine for continuously producing gas in large quantity under the action of external force.

As shown in fig. 1, in one embodiment of the present invention, the foaming substance supply means 4 may include a foam raw liquid tank 6, a water supply means 5, and a raw liquid mixing means 2. The foam stock solution tank 6 is provided with a foam stock solution outlet and a water outlet of the water supply device 5. The dope mixing apparatus 2 has a foam dope inlet 21, a water inlet 22 and a foamed substance outlet. Wherein, the foam stoste inlet 21 is communicated with the foam stoste outlet so that the foam stoste provided by the foam stoste tank 6 enters the stoste mixing device 2 from the foam stoste inlet 21, and the water inlet 22 is communicated with the water outlet so that the water provided by the water supply device 5 enters the stoste mixing device 2 from the water inlet 22.

Preferably, as shown in fig. 1, the foam generating system 100 further includes a first line 71, a second line 72, a third line 73, a fourth line 74, a first flow regulator 75, a second flow regulator 76, a third flow regulator 77, a fourth flow regulator 78, and a controller 79.

A first end of the first pipe 71 is connected to the foam concentrate outlet and a second end of the first pipe 71 is connected to the foam concentrate inlet 21. A first end of the second pipe 72 is connected to the water outlet and a second end of the second pipe 72 is connected to the water inlet 22.

A first end of the third duct 73 is connected to the foaming substance outlet and a second end of the third duct 73 is connected to the foaming substance inlet 11. A first end of the fourth conduit 74 is connected to the gas outlet and a second end of the fourth conduit 74 is connected to the inlet 12.

A first flow regulator 75 is provided on the first pipe 71, a second flow regulator 76 is provided on the second pipe 72, a third flow regulator 77 is provided on the third pipe 73, and a fourth flow regulator 78 is provided on the fourth pipe 74.

A controller 79 is connected to the first flow regulator 75 to control the flow of the foam concentrate in the first line 71, a controller 79 is connected to the second flow regulator 76 to control the flow of water in the second line 72, a controller 79 is connected to the third flow regulator 77 to control the flow of the foaming substance in the third line 73, and a controller 79 is connected to the fourth flow regulator 78 to control the flow of gas in the fourth line 74. Therefore, better foaming effect can be obtained, and the foam quality is improved.

Preferably, each of the first flow regulator 75, the second flow regulator 76, the third flow regulator 77 and the fourth flow regulator 78 may include a flow meter and a flow control valve. Each of the flow meter and the flow control valve may be provided on a corresponding one of the first line 71, the second line 72, the third line 73, and the fourth line 74. For example, a flow meter and a flow control valve of the first flow regulator 75 may be provided on the first pipe 71.

A controller 79 may be connected to each of the flow meter and the flow control valve to control the opening degree of the flow control valve based on the detected value of the flow meter, whereby the flow rate of the fluid in the line can be controlled.

As shown in fig. 1, in some examples of the present invention, the foam generating system 100 may further include a foam discharging device 8, the foam discharging device 8 having a foam inlet communicating with the foam outlet so that the foam provided from the gas-liquid mixing device 1 enters into the foam discharging device 8, and a foam discharging port communicating with the foam discharging port so that the foam discharging device 8 sprays the foam onto the target object. By providing the foam discharging means 8, it is possible to more conveniently and accurately discharge the foam onto the target object.

In one example of the invention, the foam output device 8 may include a high-lift fire truck having telescoping arms and a flexible foam delivery tube 81. The first port of the foam feed pipe 81 is the foam inlet, the second port of the foam feed pipe 81 is the foam discharge port, and a portion of the foam feed pipe 81 adjacent to the second port is provided on the telescopic arm.

By extending the telescopic arm, the second port of the foam duct 81 can be made to be closer to the target object (e.g., a fire point), that is, the foam jet port can be made to be closer to the target object, so that the foam can be more effectively jetted onto the target object, and thus, precise jetting can be achieved, so that the foam loss amount can be reduced, and the fire extinguishing efficiency can be improved. By providing the foam duct 81 with flexibility, the foam duct 81 can be more easily extended and retracted with the telescopic arm.

In another example of the present invention, the foam output device 8 may include a fire fighting robot and a flexible foam delivery tube 81. The fire fighting robot has a foam inlet and a foam discharge port, a first end of the foam feed pipe 81 is connected to the foam outlet, and a second end of the foam feed pipe 81 is connected to the foam inlet.

When spraying foam to the target object, this fire-fighting robot can move near the target object to can spray the foam to the target object more effectively, can realize accurate spraying from this, so that reduce the foam loss volume, improve the efficiency of putting out a fire. By making the foam duct 81 flexible, the foam duct 81 can be more easily moved with the fire fighting robot. The foam generating system 100 including the foam output device 8 may be used to extinguish a ground drooling fire.

In still another example of the present invention, as shown in fig. 1, the foam discharging means 8 may include a foam feeding pipe 81 and a ring-shaped foam injection pipe 82. The bubble injection tube 82 is adapted to be disposed around a storage tank 9 for storing combustible materials (e.g., a large-sized oil storage tank), that is, the bubble injection tube 82 is disposed around the storage tank 9 for storing combustible materials when the bubble injection tube 82 is in a use state. In other words, the foam injection tube 82 may be circular or elliptical.

The bubble jet pipe 82 is provided with a plurality of bubble jet ports spaced along the circumferential direction of the bubble jet pipe 82. A first end of the foam feeding pipe 81 is connected to the foam outlet and a second end of the foam feeding pipe 81 is connected to the foam injecting pipe 82, i.e., the first end of the foam injecting pipe 82 may be the foam inlet. The foam generating system 100 including the foam discharging device 8 may be used for fire extinguishing of a product oil depot, a medium station storage tank.

Preferably, a pressure regulating valve may be disposed on the fourth pipeline 74, so that the pressure and flow of the gas input into the gas-liquid mixing device 1 can be controlled by the pressure regulating valve, and the purpose of steady flow and steady pressure gas supply is achieved, thereby avoiding the influence on the foam expansion ratio and ensuring that the quality of the generated foam continuously meets the fire extinguishing requirement. That is, the invention adopts the mode of combining the gas generating device 3 and the pressure regulating valve, and can provide enough gas quantity to realize large-flow injection, simultaneously ensure the stability of the gas source and greatly improve the quality of the fire extinguishing foam.

The gas production devices 3 can be at least two groups, a plurality of groups of gas production devices 3 are arranged side by side and are communicated with the pressure regulating valve, a gas outlet of each gas production device 3 is provided with a switch valve, and when the gas production rate is insufficient, the gas production devices 3 provide gas sources by starting the corresponding switch valves in real time. According to the invention, a plurality of gas production devices 3 are adopted to produce gas, and the plurality of gas production devices 3 can start a corresponding number of gas production devices 3 in real time to operate according to the fire disaster requirement, so that the requirement of large-flow gas supply is further ensured, and large-flow continuous gas supply is realized; meanwhile, when one gas production device 3 cannot work normally, continuous gas supply can still be ensured, the reliability of the equipment is high, and the equipment is convenient to replace.

In this embodiment, the pressure regulating valve is a pressure reducing valve, and the pressure reducing valve regulates the output pressure and flow rate of the gas before the gas is input into the gas-liquid mixing device 1, and the preset pressure value of the pressure regulating valve is generally 0.8 to 1.2 MPa. The foaming material supply device 4 can be a foaming material storage tank, and the gas-liquid mixing device 1 can be arranged in the foaming material storage tank, so that the layout is compact, and the space is saved.

The gas-liquid mixing device 1 mixes the foaming substance with the gas to form foam. Flow meters are arranged at the foaming substance outlet of the foaming substance supply device 4 and the gas outlet of the gas production device 3, the flow meters measure the flow rate of the foaming substance and the flow rate of the gas, and the control device can control the pressure regulating valve according to the flow rate feedback condition, so that the ratio of the flow rate of the foaming substance entering the gas-liquid mixing device 1 to the flow rate of the gas reaches the preset standard. In other embodiments, the flow rate may be adjusted by setting the diameters of the foamed substance outlet of the foamed substance supply device 4 and the gas outlet of the gas generation device 3.

The foam generating system 100 may also include a gas tank (not shown) having an inlet and an outlet, the inlet of the gas tank being in communication with the gas outlet and the outlet of the gas tank being in communication with the inlet 12. The gas storage tank is used for storing and stably conveying gas, can ensure that large-flow high-pressure gas is injected into the gas-liquid mixing device 1 and is forcibly mixed with foaming substances. The gas storage tank can be positioned between the gas production device 3 and the pressure regulating valve.

Preferably, a filtering device is further arranged between the gas generating device 3 and the gas storage tank so as to filter the gas generated by the gas generating device 3.

In the present invention, the working pressures of the air tank and the foamed material supplying means 4 are each 0.8MPa or more, preferably 1MPa or more, and more preferably 1 to 2 MPa. This working pressure range ensures a sufficient forced mixing of the gas and foam mixture.

In the present invention, the mixing may be performed in various apparatuses capable of achieving the functions of mixing and foaming the foaming substance.

As shown in fig. 2 to 5, the gas supplied from the gas generating device 3 and the foaming substance supplied from the foaming substance supply device 4 may be mixed by the gas-liquid mixing device 1. The gas-liquid mixing device 1 has a mixing chamber with a foaming substance inlet 11 for the introduction of a foaming substance, a plurality of inlets 12 for the introduction of gas and a foam outlet 13 for the discharge of foam, a plurality of inlets 12 for the introduction of gas being able to be arranged around the foaming substance inlet 11. Wherein the gas is mixed with the foaming substance and gasified in the mixing chamber to output the foam for fire extinguishing from the foam outlet 13.

The gas-liquid mixing device 1 for mixing the foaming substance and the gas supplied from the gas generating device 3 is located outside the inlet 12 as the gas-liquid mixing device 1 for mixing the foaming substance and a liquefied medium (e.g., liquid nitrogen), and the remaining structure may be the same, and thus will not be described in detail.

A pipeline with the length of more than 40m can be connected with the foam outlet 13 of the gas-liquid mixing device 1, liquid nitrogen and foaming substances are mixed in the gas-liquid mixing device 1 and then are conveyed to the spray opening through the pipeline with the length of more than 40m, when the liquid nitrogen and the foaming substances flow in the pipeline, the liquid nitrogen and the foaming substances are fully and repeatedly mixed, and stable foam with good performance is formed before the foam is sprayed.

The foam generating system 100 described above may be disposed on fire extinguishing equipment, such as a fire extinguisher, a fire fighting foam vehicle, or a high-speed spray vehicle. The fire extinguishing apparatus generates foam through the foam generating system 100, can generate a large flow of foam, and occupies a small space.

The foam generating method of the invention can be suitable for various occasions needing to generate foam, such as fire extinguishing, heat insulation protection, food production, sound insulation material production and the like. The specific fire extinguishing and fighting can be fire extinguishing and fighting of production facilities such as chemical enterprises, oil depots, refineries and the like, runway protection of airplanes in forced landing of the airfield runways and the like.

The foam generating system 100 of the present invention can be applied to a case where the foaming material is a foam raw liquid after being simply deformed. When the foam raw liquid is used, the foam raw liquid may be mixed with water to obtain a foam mixed liquid and then mixed with gas to foam, or the foam raw liquid, water and gas may be directly mixed and foamed in a desired foaming ratio, according to a conventional method or the following embodiment. This is obviously more convenient.

According to an embodiment of the present invention, when the foam generating method is used for fire extinguishing and fire fighting, the foaming mode is as shown in fig. 2, the foaming substance inlet 11 is connected with the raw liquid mixer 2, the raw liquid mixer 2 is provided with a raw liquid inlet 21 for inputting foam raw liquid and a water inlet 22 for inputting water, the foam raw liquid and the water are respectively fed into the raw liquid mixer 2 from the raw liquid inlet 21 and the water inlet 22 to be mixed to obtain the foaming substance, and then the foaming substance is fed into the gas-liquid mixing device 1 from the foaming substance inlet 11. In order to obtain a foam mixed liquid with a proper concentration, the flow rates of the foam raw liquid and water to the raw liquid mixer 2 need to be controlled, and a flow meter, a control valve and the like can be arranged at the raw liquid inlet 21 and the water inlet 22.

In the present embodiment, it is preferable that the relationship between the diameter D6 of the water inlet 22 of the raw liquid mixer 2 and the diameter D5 of the raw liquid inlet 21 is: d6 ═ (8-14) D5; the relationship between the diameter D6 of the water inlet 22 and the diameter D2 of the foaming substance inlet 11 is: d6 ═ (1.0-1.4) D2.

The present invention will be described in detail below by way of examples.

In the following examples, each raw material was a commercially available product unless otherwise specified.

Preparation example 1

Nitrocotton (nitrogen content 12 wt%) having a water content of 20 wt% was dehydrated in a centrifuge so that the water content thereof was not more than 0.15 wt%.

100 parts by weight of the above-mentioned dehydrated nitrocellulose, 2 parts by weight of diphenylamine, 50 parts by weight of nitroguanidine and 7 parts by weight of iron trioxide were dissolved in a mixed solvent of 100 parts by weight of diethyl ether and 100 parts by weight of ethanol, and then mixed and plasticized at 20 ℃ for 60 minutes in a kneader.

Making the above mixture into cylindrical shape, drying at 30 deg.C for 8 hr to obtain 15kg weight of medicinal column, marked as chemical gas production medicine A1, with density of 1.2g/cm³N is 600, the gas production rate is 125L/s/kg, and the gas production duration is 1 min. The gas production rate testing method comprises the following steps: placing 500g of the preparation at 1m³The method comprises the following steps of starting a medicament in a box body, starting a reaction, recording the reaction duration after the reaction is finished, testing the pressure in the box body, and further calculating the volume of the generated gas.

Preparation example 2

And drying the sodium azide, the sodium nitrate and the ferrous sulfide in an oven for 2 hours at 70 ℃ to ensure that the moisture content is not more than 0.15 percent.

Mixing the dried sodium azide, aluminum oxide and magnesium trisilicate according to the weight ratio of 58:0.2:0.2, and then placing the mixture into a ball mill to be ground until the average particle size of the mixture is 15 microns.

Mixing the dried sodium nitrate, aluminum oxide and magnesium trisilicate according to the weight ratio of 3:0.2:0.2, and then placing the mixture into a ball mill to be ground until the average particle size of the mixture is 15 microns.

The ferrous sulfide is put into a ball mill to be ground until the average particle size is 15 microns.

And mixing the mixture of ferrous sulfide, sodium azide and sodium nitrate obtained by ball milling according to the weight ratio of 38:58:4, and filling the mixture into a ball mill for grinding. The ball milling time is 1 hour, and the mixture is ground to an average particle size of 10 microns. Then, drying the mixture in an oven at 70 ℃ until the water content is not more than 0.2 percent.

Adding a small amount of alcohol into the dried mixed medicine, wet-mixing the medicine powder into a mass, and putting the mass into a granulator for granulation.

Drying the granulated medicinal powder in an oven at 70 deg.C until the water content is not more than 0.2%.

Drying the granules, making into cylindrical shape, drying at 30 deg.C for 8 hr to obtain 18kg weight medicinal column, marked as chemical gas production medicine A2, with density of 1.3g/cm³N is 800, the gas production rate is 185L/s/kg, and the gas production duration is 1 min. The gas production rate was measured in the same manner as in preparation example 1.

Example 1

Mixing is carried out by adopting the mixing device shown in fig. 2 to generate foam, wherein the mixing device is provided with a mixing cavity for mixing liquid nitrogen and foam mixed liquid, the wall surface of the mixing cavity is provided with 1 foam mixed liquid inlet, 1 liquid nitrogen inlet and 1 foam outlet, and the foam outlet and the foam mixed liquid inlet are respectively positioned at two ends of the cylindrical structure. The relationship between the diameter D2 of the foam mixed liquid inlet and the diameter D3 of the gas inlet is as follows: D2/D3 is 8, and the relationship between the diameter D1 of the cylindrical structure and the diameter D2 of the foam dope inlet 21 is: D1/D2 is 1.4, the relationship between the diameter D1 of the cylindrical structure and the diameter D4 of the foam outlet is: D1/D4 is 1.2, a turbulence generator is arranged in the mixing cavity, the turbulence generator is formed into a conical structure shown in fig. 3, the conical top of the conical structure faces to the foaming substance inlet, the cross section of the turbulence generator is a circular structure, and the relationship between the diameter D7 of the turbulence generator and the diameter D2 of the foaming substance inlet is as follows: D7/D2 is equal to 1.2, and the distance L between the top end of the turbulence generator and the outlet of the liquid nitrogen at the inlet is 10 mm. The liquid nitrogen storage tank and the foam mixed liquid tank are respectively communicated with the gas-liquid mixing device through pipelines, and the angle between the direction of the liquid nitrogen pipeline inlet and the direction of the foam mixed liquid inlet is 10 degrees.

At 2m³The foam mixed liquid is stored for 1.5m in a storage tank³For example, the liquid mixture (3% type aqueous film-forming foam liquid product available from Jiangsu Jiang ya company) has a liquid pipe diameter of DN25, a working pressure in the liquid mixture storage tank of 1.2MPa, and a working pressure in the liquid nitrogen tank of 2 MPa.

For 4.52m³According to the design code of foam fire extinguishing system (GB50151-2010), the required flow rate V of the foam mixed liquid is 11.4L/min. Determining the flow rate of the liquid nitrogen according to the formula L mV/nf, wherein the foaming times m is 7, n is 710, and f is 1.01, thereby determining the flow rate of the liquid nitrogen to be 0.11L/min, feeding the liquid nitrogen and foam mixed liquid into a mixing device shown in figure 2 at the flow rate for mixing to generate foam, ejecting the foam from a foam outlet of the mixing device and conveying the foam to a fire extinguishing area for fire extinguishing, and as a result, successfully extinguishing 4.52m³The fire extinguishing time of the national standard oil pan fire is only 100s, which is far higher than that of similar foams, and the liquid nitrogen is adopted to replace an air compressor to realize the large-flow injection of the compressed air foam fire extinguishing device. The actual foam expansion times were measured to be 7.1 and the 25% liquid separation time to be 3min by the method described in foam extinguishing agent Standard (GB 15308-2006).

Example 2

Mixing is carried out by adopting the mixing device shown in fig. 2 to generate foam, wherein the mixing device is provided with a mixing cavity for mixing liquid nitrogen and foam mixed liquid, the wall surface of the mixing cavity is provided with 1 foam mixed liquid inlet, 1 liquid nitrogen inlet and 1 foam outlet, and the foam outlet and the foam mixed liquid inlet are respectively positioned at two ends of the cylindrical structure. The relationship between the diameter D2 of the foam mixed liquid inlet and the diameter D3 of the gas inlet is as follows: D2/D3 is 10, and the relationship between the diameter D1 of the cylindrical structure and the diameter D2 of the foam dope inlet 21 is: D1/D2 is 2, the relationship between the diameter D1 of the cylindrical structure and the diameter D4 of the foam outlet is: D1/D4 is 1.2, a turbulence generator is arranged in the mixing cavity, the turbulence generator is formed into a hemispherical structure shown in fig. 4, the spherical top of the hemispherical structure faces to the foaming substance inlet, the cross section of the turbulence generator is a circular structure, and the relationship between the diameter D7 of the turbulence generator and the diameter D2 of the foaming substance inlet is as follows: D7/D2 is 1.6, and the distance L between the top end of the turbulence generator and the outlet of the liquid nitrogen at the inlet is 30 mm. The liquid nitrogen storage tank and the foam mixed liquid tank are respectively communicated with the gas-liquid mixing device through pipelines, and the angle between the direction of the liquid nitrogen pipeline inlet and the direction of the foam mixed liquid inlet is 30 degrees.

At 20m³The foam mixed liquid storage tank stores 15m³The foam mixed liquid (same as example 1) is taken as an example, the pipe diameter of the liquid conveying pipe is DN150, the working pressure in the foam mixed liquid storage tank is 0.8MPa, and the working pressure in the liquid nitrogen tank is 1.5 MPa.

For 450m²According to the design code of foam fire extinguishing system (GB50151-2010), the flow V of the foam mixed liquid required to be provided is 3000L/min. The flow of the liquid nitrogen is determined according to the formula L mV/nf, wherein the foaming multiple m is set to 8, n is 710, and f is 1.17, so that the flow of the liquid nitrogen is determined to be 28.9L/min, the liquid nitrogen and foam mixed liquid is sent into the mixing device shown in the figure 2 at the flow to be mixed to generate foam, the foam is sprayed out from the foam outlet of the mixing device and then is conveyed to a fire extinguishing area through a foam output device to extinguish fire, and as a result, the 5000 cubic meter oil tank fire of 450 square meters can be successfully extinguished in only 25s, the large-flow spraying of the compressed air foam fire extinguishing device is realized, and the fire extinguishing time is far shorter than that of the existing fire fighting equipment. The foam expansion was determined to be 7.2 by the same method as in example 1, and the 25% liquid-separating time was measured to be 3 min.

Example 3

Foam generation and fire suppression were performed as in example 2, except that the flow rate of liquid nitrogen was 22L/min. The result is an extended fire extinguishing time of 55 seconds.

Example 4

Foam generation and fire suppression were performed as in example 2, except that the relationship between the diameter of the foam mixture inlet D2 and the diameter of the gas inlet D3 was: D2/D3 is 3. As a result, the extinguishing time was extended to 95 seconds. The actual foam expansion was 4.2 and the 25% liquid-separating time was 1.5min as measured in the same manner as in example 1.

Example 5

Foam generation and fire extinguishing were carried out in the same manner as in example 2, except that the distance L between the tip of the turbulence generator 14 and the outflow opening of liquid nitrogen at the inlet 12 was 150 mm. As a result, the extinguishing time was extended to 75 seconds. The actual foam expansion was measured to be 4.9 and the 25% bleeding time was 2.0min in the same manner as in example 1.

Example 6

The fire engine comprises a 25m³The liquid nitrogen storage tank truck and the high-pressure spraying truck are provided with a mixing device (same as the embodiment 1) and a foam transport truck for providing foam stock solution (anti-water-soluble film-forming foam solution AFFF/AR-3%), wherein the diameter of a spraying pipe of the high-pressure spraying truck is DN120, and a fire pump of 150L/s (1.0MPa) is provided. Water is supplied to the fire engine through a fixed fire-fighting water pipe network.

Liquid nitrogen, foam stock solution and water are respectively fed into a mixing device at 189L/min, 270L/min and 8730L/min to be mixed to generate foam, the foam is sprayed out from a foam outlet of the mixing device, the flow rate of the foam is 9000L/min, the spraying distance is 40m, and the lifting height is 30 m. The 25% liquid separating time was 3min as measured in the same manner as in example 1.

Example 7

Liquid carbon dioxide is used as a gas source, the foaming times are set to be 7, and the flow rate of the foam mixed liquid is 150L/s. The liquid carbon dioxide is jetted in a direction opposite to the flow direction of the foam liquid mixture, and the liquid carbon dioxide is jetted in a direction opposite to the foam liquid mixture in the foam generating apparatus.

The flow rate of liquid carbon dioxide was adjusted to 1.85L/s. At the moment of liquid carbon dioxide spraying, the liquid carbon dioxide is impacted by the high-speed foam mixed liquid flow, is quickly gasified and dispersed, is violently mixed with the foam mixed liquid, and generates uniform and fine foam through a foam conveying pipeline with a certain length.

Example 8

For 450m²The 5000 cubic meter oil tank fire is provided according to foam fire extinguishing system design specification (GB50151-2010)The flow rate of the foam mixed liquid should not be lower than 3000L/min, and the air supply duration time is not lower than 2 min. 8 medicament columns needing to be configured with A1 are calculated according to the formula M ═ ρ f (M +2) V/1000n, the gas production rate is at least 27000L/min, wherein f is 1.4, and the set foaming multiple M is 8.

The foam generation system shown in FIG. 1 comprises 8 chemical reaction gas-generating devices (each containing 1 gas-generating explosive column A1), gas collecting pipes, and 1 unit 20m³Foam stock solution tank (with 15m stored therein)³3 percent water film-forming foam liquid purchased from Jiangsu Jiangya company, the working pressure is 0.8MPa), 1 fire-fighting water pump and 1 gas-liquid mixing device, and the pipe diameter of a foam output pipe of the gas-liquid mixing device is DN 150. The collecting pipe of 8 chemical reaction gas making devices is provided with 3 gas outlets, and the foam stock solution storage tank is provided with a foam stock solution outlet. As shown in fig. 2, the gas-liquid mixing device has a mixing chamber of a cylindrical structure for mixing gas, foam raw liquid and water, and the wall surface of the mixing chamber is provided with 1 foam raw liquid inlet, 3 gas inlets arranged around the foam raw liquid inlet (the angle between the direction of each gas inlet and the direction of the foam material inlet is 40 °), 1 water inlet and 1 foam outlet, and the foam outlet and the foam raw liquid inlet are respectively positioned at two ends of the cylindrical structure. The relationship between the diameter of the foaming substance inlet D2 and the diameter of each gas inlet D3 is: D2/D3 is 3.5, the relationship between the diameter D1 of the cylindrical structure and the diameter D2 of the foam dope inlet is: D1/D2 equals 1.6, the relationship between the diameter D1 of the cylindrical structure and the diameter D4 of the foam outlet is: d1 ═ D4. A vortex generator is arranged in the mixing cavity, the vortex generator is formed into a conical structure shown in figure 3, the conical top of the conical structure faces to the foaming substance inlet, the cross section of the vortex generator is a circular structure, and the relationship between the diameter D7 of the vortex generator and the diameter D2 of the foaming substance inlet is as follows: D7/D2 is 1.3, the distance L between the tip of the turbulator and the outlet opening of the gas at the inlet opening is 10 mm. Wherein, the gas outlet of each chemical reaction gas making device is communicated with the gas inlet of the mixing cavity, the foam stock solution outlet of the foam stock solution tank is communicated with the foam stock solution inlet of the mixing cavity, and water is provided by a fire hydrant. The chemical reaction gas making device and the foam raw liquid tank are respectively mixed with gas and liquid through pipelinesThe device is communicated, and the length of the pipeline enables the gas generated by the chemical reaction gas-making device to enter the gas-liquid mixing device within 20 seconds.

The chemical reaction gas-making device is started in an electric shock ignition mode to generate gas. The generated gas, 90L/min foam stock solution and 2910L/min fire water are fed into a mixing device to be mixed to generate foam, and the foam is sprayed out of a foam outlet of the mixing device. The actual foam expansion factor was 7.1 and the 25% drainage time of the foam was 3min, as determined by the method described in foam fire extinguishing agent Standard (GB 15308-2006).

The foam is conveyed to a fire extinguishing area through a foam output device to extinguish fire, and as a result, 450m of foam is successfully extinguished²The 5000 cubic meter oil tank fire only needs 25s, and the large-flow injection of the compressed air foam fire extinguishing device is realized.

Example 9

For 450m²According to the design specification of a foam fire extinguishing system (GB50151-2010), the flow of the foam mixed liquid required to be provided is not lower than 3000L/min, and the air supply duration is not lower than 2 min. 6 medicament columns needing to be configured with A2 are calculated according to the formula M ═ ρ f (M +2) V/1000n, the gas production rate is at least 27000L/min, wherein f is 1.4, and the set foaming multiple M is 8.

The foam generation system shown in FIG. 1 comprises 6 chemical reaction gas-generating devices (each containing 1 gas-generating charge A2), gas collecting pipes, and 1 unit 20m³Foam stock solution tank (with 15m stored therein)³The anti-water-soluble film-forming foam liquid AFFF/AR-3 percent, the working pressure is 1MPa), 1 fire-fighting water pump and 1 gas-liquid mixing device, and the pipe diameter of a foam output pipe of the gas-liquid mixing device is DN 150. The gas collecting pipe of the 6 chemical reaction gas making devices is provided with 3 gas outlets, and the foam stock solution storage tank is provided with a foam stock solution outlet. As shown in FIG. 2, the gas-liquid mixing apparatus has a mixing chamber for mixing gas, foam raw liquid and water, and the wall surface of the mixing chamber is provided with 1 foam raw liquid inlet, 3 gas inlets arranged around the foam raw liquid inlet (the angle between the direction of each gas inlet and the direction of the foam material inlet is 30 degrees), 1 water inlet, and 1 foam outletThe port and the foam stock solution inlet are respectively positioned at two ends of the cylindrical structure. The relationship between the diameter of the foaming substance inlet D2 and the diameter of each gas inlet D3 is: D2/D3 is 2, and the relationship between the diameter D1 of the cylindrical structure and the diameter D2 of the foam concentrate inlet is: D1/D2 is 1.4, the relationship between the diameter D1 of the cylindrical structure and the diameter D4 of the foam outlet is: D1/D4 is 1.2, a turbulence generator is arranged in the mixing cavity, the turbulence generator is formed into a hemispherical structure shown in fig. 4, the spherical top of the hemispherical structure faces to the foaming substance inlet, the cross section of the turbulence generator is a circular structure, and the relationship between the diameter D7 of the turbulence generator and the diameter D2 of the foaming substance inlet is as follows: D7/D2 is 1.2, and the distance L between the tip of the turbulator and the outlet of the gas at the inlet is 20 mm. Wherein, the gas outlet of the gas collecting pipe of the chemical reaction gas making device is communicated with the gas inlet of the mixing cavity, the foam stock solution outlet of the foam stock solution tank is communicated with the foam stock solution inlet of the mixing cavity, and water is provided by the fire hydrant. The chemical reaction gas making device and the foam raw liquid tank are respectively communicated with the gas-liquid mixing device through pipelines, and the length of the pipelines enables gas generated by the chemical reaction gas making device to enter the gas-liquid mixing device within 30 seconds.

Example 10

Foam was generated and fire was extinguished using this foam in the manner of example 9, except that the relationship between the diameter of the foaming substance inlet D2 and the diameter of each gas inlet D3 was: D2/D3 is 7. As a result, 450m of the mixture was successfully extinguished²The 5000 cubic meter oil tank requires 95 seconds for fire.

Example 11

A foam generating system similar to that in example 9 is used for extinguishing 5-ten-thousand cubic meter storage tanks in an oil depot by flowing fire in a full area, the diameter of the storage tank is 60m, the area is 2826 square meters, and in contrast, 2 sets of foam fire extinguishing devices are configured, each set of the device comprises a special vehicle (comprising an instant chemical reaction gas generating device (containing gas medicine A2) and a gas storage device) and a high-speed spraying vehicle (comprising a gas-liquid mixing device and a foam output device), and each high-speed spraying vehicle is configured with a foam transport vehicle to provide foam liquid and supply water to the fire fighting vehicle through a fixed fire fighting water pipe network. When fire extinguishment is carried out, the 2 high-pressure spray trucks occupy space in the upwind direction of the storage tank on fire, and sprayed foam is sprayed into the tank from the upwind direction to complete fire extinguishment.

DN40 is taken from the pipe diameter of the inlet and outlet of the instant chemical reaction gas production device, and the gas production capacity is not lower than 4500 Nm; taking DN150 from the pipe diameter of an injection pipe of the high-pressure jet vehicle; A150L/s (1.0MPa) fire pump is configured, the flow rate of the foam mixed liquid can be 9000L/min, the spraying distance is 40m, the lifting height is 30m, and the pressure-stabilizing spraying of the foam mixed liquid is realized. As a result, the fire extinguishing in the whole area only needs 2 min.

Example 12

The foam generation system shown in FIG. 1 comprises 6 chemical reaction gas-generating devices (each containing 1 gas-generating charge A2), gas collecting pipes, and 1 unit 20m³A foam mixed liquid tank (the source of the foam mixed liquid is the same as that in the embodiment 1, the working pressure is 1MPa) and 1 gas-liquid mixing device, wherein the pipe diameter of a foam output pipe of the gas-liquid mixing device is DN 150. The gas collecting pipe of the 6 chemical reaction gas making devices is provided with 3 gas outlets, and the foam mixed liquid storage tank is provided with a foam mixed liquid outlet. The gas-liquid mixing device is shown in FIG. 2 and has a device for mixing gas and liquidThe hybrid chamber that the foam mixes the liquid, be equipped with 1 foam on the wall of this hybrid chamber and mix the liquid import, 3 gas inlets (the angle between the direction of every gas inlet and the direction of foaming material import is 30 degrees) and 1 foam export that the liquid import of mixed liquid of surrounding foam set up, foam export and foam mix the liquid import and be located tubular structure's both ends respectively. The relationship between the diameter of the foaming substance inlet D2 and the diameter of each gas inlet D3 is: D2/D3 is 2, and the relation between the diameter D1 of the cylindrical structure and the diameter D2 of the foam mixed liquid inlet is as follows: D1/D2 is 1.4, the relationship between the diameter D1 of the cylindrical structure and the diameter D4 of the foam outlet is: D1/D4 is 1.2, a turbulence generator is arranged in the mixing cavity, the turbulence generator is formed into a hemispherical structure shown in fig. 4, the spherical top of the hemispherical structure faces to the foaming substance inlet, the cross section of the turbulence generator is a circular structure, and the relationship between the diameter D7 of the turbulence generator and the diameter D2 of the foaming substance inlet is as follows: D7/D2 is 1.2, and the distance L between the tip of the turbulator and the outlet of the gas at the inlet is 20 mm. Wherein, the gas outlet of each chemical reaction gas making device is communicated with the gas inlet of the mixing cavity, and the foam mixed liquid outlet of the foam mixed liquid tank is communicated with the foam mixed liquid inlet of the mixing cavity. The chemical reaction gas making device and the foam mixing liquid tank are respectively communicated with the gas-liquid mixing device through pipelines, and the length of the pipelines enables gas generated by the chemical reaction gas making device to enter the gas-liquid mixing device within 30 seconds.

The chemical reaction gas-making device is started in an electric shock ignition mode to generate gas. The gas formed by the reaction and a foam mixture of 3000L/min were fed into the mixing apparatus shown in FIG. 2 at the above flow rate to be mixed to generate foam, and the foam was ejected from the foam outlet of the mixing apparatus. The actual foam expansion factor was 7.1 and the 25% drainage time of the foam was 3min, as determined by the method described in foam fire extinguishing agent Standard (GB 15308-2006).

The foam is conveyed to a fire extinguishing area through a foam output device to extinguish fire, and as a result, 450m of foam is successfully extinguished²The 5000 cubic meter oil tank fire only needs 25s, and the large-flow injection of the compressed gas foam fire extinguishing device is realized.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A method of generating foam, the method comprising mixing a gas with a foamable material such that the foamable material generates foam, wherein at least part of the gas is generated instantaneously by a gas source;

wherein the foaming substance is a foam mixed solution;

the gas source is at least one of sodium azide, ammonium nitrate, nitrocellulose, hexogen gas producing medicines and nitroguanidine gas producing medicines;

when the gas source is a chemical gas-producing substance, the using amount of the chemical gas-producing substance is determined by the gas production amount of the chemical gas-producing substance and the foaming multiple, and the using amount of the chemical gas-producing substance is calculated according to the following formula:

M＝ρf(m+2)V/1000n

wherein M is the mass of the chemical gas-producing substance needed in unit time, and the unit is kg/min, rho is the density of the chemical gas-producing substance, and the unit is kg/M³F is a correction coefficient, the value is in the range of 1-1.4, m is a set foaming multiple, the value is in the range of 5-200, V is the volume flow of the foam mixed liquid, the unit is L/min, n is the ratio of the volume of gas which can be generated by the chemical gas generating substance to the volume of the chemical gas generating substance, and the value is between 100 and 800.

2. The foam generating method as recited in claim 1, wherein M in M ═ ρ f (M +2) V/1000n is in the range of 5 to 20.

3. The foam generating method as recited in claim 1, wherein M in M ═ ρ f (M +2) V/1000n is in the range of 6 to 8.

4. A foam generating method as claimed in any of claims 1 to 3, wherein the mixing conditions include a mixing temperature of from-30 ℃ to 60 ℃.

5. A foam generating method as claimed in any of claims 1 to 3, wherein the mixing conditions include a mixing temperature of from-10 ℃ to 40 ℃.

6. A foam generating method as claimed in any of claims 1 to 3, wherein the mixing conditions include a mixing temperature of 0 to 40 ℃.

7. Use of a foam generating method according to any of claims 1 to 6 for extinguishing fires.

8. A method of extinguishing a fire by generating foam using the foam generating method of any one of claims 1 to 6 and then outputting the foam for extinguishing the fire.